This states that the rhombus is a special case of the kite.
Eric W. Weisstein. "Kite." From MathWorld--A Wolfram Web Resource.http://mathworld.wolfram.com/Kite.html
My current book (McDougal Littell-Geometry Applying, Reasoning and
Measuring)says opposite sides must be different.
I don't think it should be necessary for the opposite sides to be different.
This is another example of great discussion in math class.
I like to discuss concepts to show that math is not just a bunch of rules that
never evolve. We talk about the relative newness of fractal geometry, the many
ways we do proof now that we didn't do when I went to high school in the 60's.

On May 5 2005, Susan wrote:
> I know we had a big discussion about parallelograms, but now I need
> help. Some textbooks (especially the older ones) have rhombii as a
> subset of kites, but the newer ones do not. It seems like the way
> you develop the area formulas make them related. Is a rhomus a kite?
> Is a square a kite? Any ideas? Has it changed over the years, or
> is it just me?

This material is based upon work supported by the
National Science Foundation under Grant DUE-0226284.
Any opinions, findings, and conclusions or recommendations
expressed in this material are those of the author(s)
and do not necessarily reflect the views of the
National Science Foundation.